1. Field of the Invention
This invention relates to an igniter to be disposed in an air bag inflation gas generator or the like.
2. Description of the Prior Art
A prior shock absorber to protect a passenger car driver from shocks at collision accidents comprises an air bag and a gas generator to inflate the air bag with gas. At a collision accident of a passenger car, explosives or other gas generating agents having a similar composition thereto, which are charged in the gas generator, are ignited and burnt to produce gas. The air bag is instantaneously inflated by the resultant gas for protecting the driver against any collision shocks, thereby avoiding possible serious injury of the driver.
And, in the above type of air bag inflation gas generator, an igniter is disposed to ignite an ignition agent which burns gas generating agents.
FIG. 2 shows a conventional igniter which is disclosed in Japanese Utility Model Application Laid-open Print No. 108460/1992 for example. In the drawing, the reference numeral 11 represents a cylindrical igniter holder.
At the front of the igniter holder 11, an igniting section 12 is formed.
At the leading end of the igniter holder 11, a cup 13 is inserted. And a separator 15 is inserted in the cup 13.
In the front side of the separator 15, priming charge 17 is accommodated. And in the back side of the separator 15, a charge holder 21 is disposed to accommodate an igniting agent 19.
And, in the rear opening of the igniter holder 11, a harness supporter 23 is inserted with its top ahead and fixed within the igniter holder 11 by a caulking section 24 of the igniter holder 11.
In this harness supporter 23, harnesses 25 are plugged. These harnesses 25 are electrically connected with a heater 29 which is disposed in contact with the igniting agent 19 via lead terminals 27 of a header 26.
In FIG. 2, the reference numeral 31 represents a glass sintered member of the header 26, and 33 represents ferrite beads.
With the igniter configured as described above, when a car crashes, electricity is sent to the heater 29 through the harnesses 25 and the lead terminals 27. Then the temperature of the heater 29 rises to ignite the igniting agent 19 which in turn ignites the priming charge 17, causing an ignition agent to burn.
But, the above conventional igniter has disadvantages that when a charge holder 21 is charged with static electricity, this static electricity is discharged from the charge holder 21 to lead electrodes 27 and, in the worst case, the igniting agent might ignite. Therefore, this igniter is not preferable to be used as the igniter for an air bag inflation gas generator which is required to be very reliable.